Cache device

Abstract

A cache device interposed between a processor and a memory device, including: a cache memory storing data from the memory device; a buffer holding output data output from the processor; a control circuit determining, on the basis of a request to access the memory device, whether a cache hit has occurred or not and, if a cache miss has occurred, storing the output data in the buffer in response to the access request, outputting a read request for reading the data in a line containing data requested by the access request from the memory device, storing data output from the line of the memory device into the cache memory, and storing the output data from the buffer into the cache memory.

1. A cache device interposed between a processor and a memory device, comprising:
 a cache memory to store data from the memory device; 
 a plurality of buffers to hold output data output from the processor; and 
 a control circuit to determine, on the basis of a request to access the memory device, whether a cache hit has occurred or not and, if a cache miss has occurred, storing the output data in one of the plurality of buffers in response to the request to access the memory device, outputting a read request for reading the data in a line containing data requested by the request to access the memory device, storing data output from the line of the memory device into the cache memory, and storing the output data from the one of the plurality of buffers into the cache memory, 
 wherein the plurality of buffers, each including the data in a different line, 
 wherein: if an address of the output data is not within the address range of the data in the line included in the one of the plurality of buffers, another one of the plurality of buffers is alternately selected, the address of the output data being within the address range of the data in the line included in another one of the plurality of buffers. 
 
     
     
       2. A cache device interposed between a processor and a memory device, comprising:
 a cache memory to store data from the memory device; 
 a buffer to hold output data output from the processor; and 
 a control circuit to determine, on the basis of a request to access the memory device, whether a cache hit has occurred or not and, if a cache miss has occurred, storing the output data in the buffer in response to the request to access the memory device, outputting a read request for reading the data in a line containing data requested by the request to access the memory device, storing data output from the line of the memory device into the cache memory, and storing the output data from the buffer into the cache memory, 
 wherein: the amount of the output data transferred from the buffer to the cache memory is set equal to the capacity of the line; and when the access request is a write access request and the write access request results in a cache miss, data read from the memory device for the cache miss is cancelled. 
 
     
     
       3. The cache device according  claim 1 , wherein: the amount of the output data transferred from the buffer to the cache memory is set equal to the capacity of the line; and when the access request is a write access request and the write access request results in a cache miss, data read from the memory device for the cache miss is cancelled.